It has become a journalistic cliché and therefore an inevitable part of the prerelease discussion of “Sicko” to refer to Michael Moore as a controversial, polarizing figure. While that description is not necessarily wrong, it strikes me as self-fulfilling (since the controversy usually originates in media reports on how controversial Mr. Moore is) and trivial. Any filmmaker, politically outspoken or not, whose work is worth discussing will be argued about. But in Mr. Moore’s case the arguments are more often about him than about the subjects of his movies.

Some of this is undoubtedly his fault, or at least a byproduct of his style. His regular-guy, happy-warrior personality plays a large part in the movies and in their publicity campaigns, and he has no use for neutrality, balance or objectivity. More than that, his polemical, left-populist manner seems calculated to drive guardians of conventional wisdom bananas. That is because conventional wisdom seems to hold, against much available evidence, that liberalism is an elite ideology, and that the authentic vox populi always comes from the right. Mr. Moore, therefore, must be an oxymoron or a hypocrite of some kind.

So the table has been set for a big brouhaha over “Sicko,” which contends that the American system of private medical insurance is a disaster, and that a state-run system, such as exists nearly everywhere else in the industrialized world, would be better. This argument is illustrated with anecdotes and statistics — terrible stories about Americans denied medical care or forced into bankruptcy to pay for it; grim actuarial data about life expectancy and infant mortality; damning tallies of dollars donated to political campaigns — but it is grounded in a basic philosophical assumption about the proper relationship between a government and its citizens.

Mr. Moore has hardly been shy about sharing his political beliefs, but he has never before made a film that stated his bedrock ideological principles so clearly and accessibly. His earlier films have been morality tales, populated by victims and villains, with himself as the dogged go-between, nodding in sympathy with the downtrodden and then marching off to beard the bad guys in their dens of power and privilege. This method can pay off in prankish comedy or emotional intensity — like any showman, Mr. Moore wants you to laugh and cry — but it can also feel manipulative and simplistic.

In “Sicko,” however, he refrains from hunting down the C.E.O.’s of insurance companies, or from hinting at dark conspiracies against the sick. Concentrating on Americans who have insurance (after a witty, troubling acknowledgment of the millions who don’t), Mr. Moore talks to people who have been ensnared, sometimes fatally, in a for-profit bureaucracy and also to people who have made their livings within the system. The testimony is poignant and also infuriating, and none of it is likely to be surprising to anyone, Republican or Democrat, who has tried to see an out-of-plan specialist or dispute a payment.

If you listen to what the leaders of both political parties are saying, it seems unlikely that the diagnosis offered by “Sicko” will be contested. I haven’t heard many speeches lately boasting about how well our health care system works. In this sense “Sicko” is the least controversial and most broadly appealing of Mr. Moore’s movies. (It is also, perhaps improbably, the funniest and the most tightly edited.) The argument it inspires will mainly be about the nature of the cure, and it is here that Mr. Moore’s contribution will be most provocative and also, therefore, most useful.

“Sicko” is not a fine-grained analysis of policy alternatives. (You can find some of those in a recently published book called “Sick,” by Jonathan Cohn, and also in the wonkier precincts of the political blogosphere.) This film presents, instead, a simple compare-and-contrast exercise. Here is our way, and here is another way, variously applied in Canada, France, Britain and yes, Cuba. The salient difference is that, in those countries, where much of the second half of “Sicko” takes place, the state provides free medical care.

With evident glee (and a bit of theatrical faux-naïveté) Mr. Moore sets out to challenge some widely held American notions about socialized medicine. He finds that British doctors are happy and well paid, that Canadians don’t have to wait very long in emergency rooms, and that the French are not taxed into penury. “What’s your biggest expense after the house and the car?” he asks an upper-middle-class French couple. “Ze feesh,” replies the wife. “Also vegetables.”

Yes, the utopian picture of France in “Sicko” may be overstated, but show me the filmmaker — especially a two-time Cannes prizewinner — who isn’t a Francophile of one kind or another. Mr. Moore’s funny valentine to a country where the government will send someone to a new mother’s house to do laundry and make carrot soup turns out to be as central to his purpose as his chat with Tony Benn, an old lion of Old Labor in Britain. Mr. Benn reads from a pamphlet announcing the creation of the British National Health Service in 1948, and explains it not as an instance of state paternalism but as a triumph of democracy.

More precisely, of social democracy, a phrase that has long seemed foreign to the American political lexicon. Why this has been so is the subject of much scholarship and speculation, but Mr. Moore is less interested in tracing the history of American exceptionalism than in opposing it. He wants us to be more like everybody else. When he plaintively asks, “Who are we?,” he is not really wondering why our traditions of neighborliness and generosity have not found political expression in an expansive system of social welfare. He is insisting that such a system should exist, and also, rather ingeniously, daring his critics to explain why it shouldn’t.

SICKO

Opens today in Manhattan.

Written and directed by Michael Moore; edited by Christopher Seward, Dan Sweitlik and Geoffrey Richman; produced by Mr. Moore and Meghan O’Hara; released by Lionsgate and the Weinstein Company. At the Lincoln Square, 1998 Broadway, at 68th Street. Running time: 123 minutes.